package org.nw.web.login;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.nw.web.AbsBaseController;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;


/**
 * 验证码处理
 * 
 * @author fangw
 */
@Controller
public class VerifyCodeController extends AbsBaseController {

	final private static Logger log = Logger.getLogger(VerifyCodeController.class);

	/**
	 * 验证码产生器
	 * 
	 * @param request
	 * @param response
	 * @return
	 */
	@RequestMapping("/verifyCodeGenerator.do")
	public ModelAndView login(HttpServletRequest request, HttpServletResponse response) {
		// 设置页面不缓存
		response.setHeader("Pragma", "No-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0);

		// 在内存中创建图象
		int width = 60, height = 20;
		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

		// 获取图形上下文
		Graphics g = image.getGraphics();

		// 生成随机类
		Random random = new Random();

		// 设定背景色
		g.setColor(getRandColor(200, 250));
		g.fillRect(0, 0, width, height);

		// 设定字体
		g.setFont(new Font("Times New Roman", Font.PLAIN, 18));

		// 画边框
		// g.setColor(new Color());
		// g.drawRect(0,0,width-1,height-1);

		// 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
		g.setColor(getRandColor(160, 200));
		for(int i = 0; i < 155; i++) {
			int x = random.nextInt(width);
			int y = random.nextInt(height);
			int xl = random.nextInt(12);
			int yl = random.nextInt(12);
			g.drawLine(x, y, x + xl, y + yl);
		}

		// 取随机产生的认证码(4位数字)
		String randCode = "";
		for(int i = 0; i < 4; i++) {
			String rand = String.valueOf(random.nextInt(10));
			randCode += rand;
			// 将认证码显示到图象中
			g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));// 调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
			g.drawString(rand, 13 * i + 6, 16);
		}
		// 将认证码存入SESSION
		request.getSession(true).setAttribute("verifyCode", randCode);

		// 图象生效
		g.dispose();

		// 输出图象到页面
		try {
			OutputStream os = response.getOutputStream();
			ImageIO.write(image, "JPEG", os);
			os.flush();
			os.close();
		} catch(IOException e) {
			log.error(e);
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * 给定范围获得随机颜色
	 * 
	 * @param fc
	 * @param bc
	 * @return
	 */
	private Color getRandColor(int fc, int bc) {
		Random random = new Random();
		if(fc > 255) {
			fc = 255;
		}
		if(bc > 255) {
			bc = 255;
		}
		int r = fc + random.nextInt(bc - fc);
		int g = fc + random.nextInt(bc - fc);
		int b = fc + random.nextInt(bc - fc);
		return new Color(r, g, b);
	}

}
